Impulse-transmitting device.



J. A. KROPP.

IMPULSE TRANSMITTING DEVICE.

APPLICATION FILED OCT. n. 1916.

Patented Apr. 9, 1918.

hive/17hr. I John A. Kropp UNITED satires rnrnnr orrrcn.

JOHN A. KROPIP, OAK PARK, ILLINOIS, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, 013 NEW YORK, N. Y., A CORPORATION OF NEW YORK.

I V IMPULSE-TRANSMITTING DEVICE.

menace.

Specification of Letters Patent.

Patented Apr. 9, 1918.

To all whom it may concern:

Be it known that I, JOHN A. Knorr, a citizen of the United States, residing at Oak Park, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Impulse-Transmitting Devices, of which the following is a full, clear, concise, and exact description.

This invention relates to impulse transmitting devices or senders, and more particularly relates to senders for controlling selectively operable switching devices employed in automatic and semi-automatic telephone exchanges.

The main object of this invention is to provide a sender of the above defined character, and arranged to transmit impulses of varying frequencies to selectively control the operation of the switching devices.

Another object is to provide a sender arranged to send out impulses in accordance with a certain numerical designation, and

in which the interval of time required for sending impulses designated by a certain numeral or character is thesame as the time required for sending impulses designated by any other numeral or character.

In order to attain the above defined objects, according to the principal feature of this invention, the impulse transmittingdevice is provided with a vibrating member of variable operating length to transmit impulses of different or varying frequencies.

The above feature with others will be more clearly pointed out in the ensuing de scription and claims.

In the drawings, Figure 1 is a perspective view of the improved sender; Fig. 2 is a detail view of a modified portion of the invention; and Fig. 3 is a plan view of the sender showing the arrangement of the slots, and the controlling finger lever.

Referring in detail to the drawings, 1 represents a casing for inclosing the mechanism employed in the sender. Permanent bar magnets 7 and 9 are offset at one end and these ofiset ends are fastened together to form a U-shaped structure. A wire 8, forming part of the controlling circuit, is wound around the magnets 7 and 9 respec tively in the manner shown in Fig. 1. A

yibrati'ng member 10, of magnetic material,

has one of its ends rigidly secured between the offset portions of the magnets and its other end free to vibrate between the free ends of the magnets. The free ends of the magnets are of like polarity, and the free end of the vibrating member is of opposite polarity to that of the free ends of bar magnets. In accordance with the wellknown physical law, the magnetic flux through each arm 7 and 9 is alternately increased and decreased when the member 10 is set in vibration. This change in magnetic flux induces current, in a circuit including the wire 8, of a frequency corresponding to the frequency of vibration of the reed.

An apertured block 6 is slidably mounted i on the vibrating member, and is prevented from moving in a vertical or lateral direction by the magnets? and 9. The opening in block 6 isonly of suflicient size to receive the vibrating member, so that only the free end of this member .can be vibrated. It will be understood that as the block is moved along the vibrating member, thelength of this vibrating portion is varied, which changes the frequency of vibration of the member.

Brackets and 3 are pivotally supported to swing horizontally 1n the frame (not shown). The bracket 3 has an angular arm 4, which is notched at its free end. An L- shaped rod 5 fastened to the block 6 engages the notched end of the arm 4 to control the movement of the block along the vibrating member 10. A bar 13 having apertured upturned ends, forming lugs 14 and 15, is 'p-ivotally secured to the brackets 2 and 3, and operates to space these brackets apart. A rod 16 is secured to the apertures of lugs 14 and 15 and serves as an axis about which a yoke or U-shaped member 37 rotates. To the arms of this U-shaped member 37there are secured the spaced parallel rods 17 and 18, the purpose of which will be hereinafter described. A finger piece 19 is fastened to opening 20 in the top of the casing. I

A bell-crank lever 24:, notched at one end to form lugs 27 and 28, is p-ivotally mounted the top of the yoke and extends through an I this lever. A lug 29 of the member 25 is normally held in engagement with the vibrating member by spring 80, and functions to prevent the vibrating member from operating. Another lug 26 of the member 25 normally engages the rod 18. The rod 17 -Opposite each character a slot 21 is provided,

into which the finger piece 19 can be pulled. A pointer 40 attached to the finger piece 19 indicates the position in which finger piece 19 should be operated to transmit impluses of a frequency corresponding to that of the indicated character. When the finger piece is moved so that the pointer 40 is over any one ofthe characters, the finger piece is in a position to be pulled into the slot opposite that character. The normal position of the pointer in the drawings is over the character 1.

The operation of the above described mechanism is as follows:

The operator moves the finger piece 19 opposite a slot corresponding to the digit of the desired number, and then pulls the finger piece into this slot. By moving thefinger piece 19 to the desired position, the brackets 2 and 3 are rotated on their pivots 81 and 82 respectively. The rotation of bracket 3 causes-the arm 4 to move the block 6 along the vibrating member 10. The movement of the block varies the length of thevibratory portion of the member 10 to change its frequency of vibration. This variation in length depends upon the positioning of finger piece 19. Therefore, it is very evident that the frequency of the current induced in the wire Sdepends upon the position to which the finger piece is moved.

The bell-crank lever is not rotated at this time because rods 17 and 18 move horizontally into the groove provided therefor. When the finger piece is pulled into the slot opposite the selected character, rod 18 engages lug 26 to pull the T-shaped member out of engagement with the member '10, which starts vibrating to induce a current in the wire 8 of a frequency depending upon the positioning of the lever as above described.

At the same time, rod 17 engages lug 27 of the bell-crank lever and rotates it clockwise until the arm 24 comes into engagement with lug 39. The purpose of this movement is to position member 25 so that when the finger piece is released and the member 25 is moved to the left by spring 80, the lug 29 will be raised suficiently to engage the end of the vibrating member 10. The bell-crank lever is held in this position by spring 30 which is so arranged that nor- Laeaaae mally its line of action is below'the pivot about which the bell-crank lever rotates, so that it holds lug 27 in engagementwith rod 17. When the bell-crank lever is rotated by rod 17, as the finger piece is pulled into a slot, the line of action of said spring is changed so that it is above the pivot and moves lug 28 into engagement with rod 17 and holds it in this position.

When the operator releases the finger piece 19, the spring 22 causes it to be drawn out of the slot, whereupon it is returned to its normal position byspring 31 attached to the bracket 2 and the frame 1. As the finger piece 19 moves out of the notch with which it was in engagement, the lug 29 of the T-shaped member 25 engages the end of the vibrating member in the manner above described.

' At this time rod 17 hasmoved far enough to engage lug 28 and this lug in turn causes the bell-crank lever to be rotated counterclockwise. This rotation causes the member 25 to pull the free end of the member 10 downward. It will be seen that where the free end of the vibrating member is released it will start vibrating.

In Fig. 2 the vibrating member 10 is arranged to make and break a contact between itself and spring 31'. A spring 31 and vibrating member 10 control a breakpoint in a circuit (not shown), which is normally closed by the member 10 being held in engagement with the contact spring 31. vWhen the vibrating member is set in vibration in a manner above described, the circuit is opened and closed at a frequency corresponding to that of the vibrating member. Sliding member 6 is arranged to slide along the member 10 to change its vibrating length in the same manner as above described.

What is claimed is:

1. In an impulse transmitting device, a vibrating member, means to normally maintain said member in a resting position, means associated with said member to vary its operating length, and a single means to control the two first mentioned means.

2. In an impulse transmitting device, a

vibrating member, means for normally maintaining said member in a resting position, means associated with said member to vary its operating length, and a movable lever for controlling both of said means.

3; In an impulse transmitting device, a vibrating member, means to normally main- .tain said member in a resting position,

4. in an impulse transmitting device, a vibrating member arranged to send current impulses, means for normally maintaining said member in a resting position, a sliding 5 member associated with said vibrating member to vary its operating length, a movable lever mounted for movement in one direction to operate said sliding'member, and

in another direction to release said means to allow said vibrating member to vibrate. 10

In Witness whereof, I hereunto subscribe my name this 27th day of Sept, A. D. 1916.

JOHN A. KROPP. 

